1. Field of the Invention
This invention relates to an endoscope having a driving means driving a curvable part and treating tool raising device within an insertable part.
2. Related Art Statement
Recently, there is extensively used an endoscope whereby an organ within a body cavity can be observed by inserting an elongate insertable part into the body cavity or, as required, various curing treatments can be made by using treating tools inserted through a treating tool channel.
Now, in the above mentioned endoscope, a curvable part curvable on the tip side is provided in the insertable part so as to be operatable to be curved. There is a means of operating the above mentioned curvable part wherein a curving operation knob is provided in the operating part and is rotated and operated or wherein such driving means as a motor is provided near the curvable part.
A small endoscope simplified in the structure and provided with a driving means such as a vibration wave motor near the curvable part of the insertable part is shown, for example, in the publication of a Japanese patent application laid open No. 106126/1986. There are advantages that, when the driving means is thus provided near the curvable part, the response to the curving operation will be higher, the inspection will be able to be made with the minimum operation and the pain of the patient will be able to be reduced.
On the other hand, the curvable part will be curved in use so frequently as to be more likely to damage the contents than the other parts of the insertable part. Therefore, within the curvable part, the contents are covered with a protective tube to prevent damage.
Now, the length of the contents protecting tube provided within the curvable part is so set that the protecting tube end surface may come closer to the operating part side than the connecting piece of the articulated frame at the rearmost end.
Also, the contents within the insertable part are packed as much as possible so as to make the outside diameter of the insertable part as fine as possible to reduce the pain of the patient.
The vibration wave motor driving part is larger in outside diameter than the driving power transmitting part and requires a larger space.
Therefore, if the driving part is arranged in position in which the area occupied by the contents within the insertable part is maximum such as in the part covered by the above mentioned protecting tube, the insertable part will have to be made larger in outside diameter by an amount equal to the difference between the cross-sectional area of the driving part and the cross-sectional area of the driving power transmitting part so that the pain of the patient will become larger.
In an endoscope provided with a treating tool raising device in the tip part of the insertable part, it is considered to provide a driving means such as a vibrating wave motor within the insertable part as a means of driving this treating tool raising device. In such a case, too, if the above mentioned driving means is arranged in the position in which the area occupied by the contents within the insertable part is maximum, the insertable part will become larger in outside diameter.
In the above mentioned related art example, four wire driving parts are provided as curving driving means and are arranged in the same positions in the position relation in the axial direction of the insertable part. Therefore, there are four wire driving parts in the cross-sectional area of the insertable part including the above mentioned wire driving parts. As this wire driving part is larger in outside diameter than the drive transmitting part, the outside diameter of the insertable part will be determined by the sum of the sizes of the four wire driving parts and the size of the other contents contained in the part in which these wire driving parts exist. Therefore, there are problems that, if the four wire driving parts exist in the same crosssection, the insertable part will become larger in outside diameter and the pain of the patient will become larger.